Multiple unit trailers and containers



Dec. 29, 1964 w. BENNETT ETAL 3,163,306

MULTIPLE UNIT TRAILERS AND CONTAINERS Filed May 17, 1961 14 Sheets-Sheet l 1N VENTORS.

M175? BEAM/Era; STEPHEN EAR/(ER, Pena/m2. M. HEM/MILLER,

W. BENNETT ETAL MULTIPLE UNIT TRAILERS AND CONTAINERS Dec. 29, 1964 14 Sheets-Sheet 2 Filed May 17. 1961 Dec. 29, 1964 w. BENNETT ETAL 3,163,306

MULTIPLE UNIT TRAILERS AND CONTAINERS Filed May 17. 1961 14 Sheets-Sheet 4 INVENTORS R .Be/wverr .102 /.i7a 17;- J5 J02 STEPHE g 0.? r ficvmz, MHEWMIME-g Dec. 29, 1964 w. BENNETT ETAL MULTIPLE UNIT TRAILERS AND CONTAINERS Filed May 17, 1961 Dec, 29, 1964 w. BENNETT ETAL MULTIPLE UNIT TRAILERS AND CONTAINERS 14 Sheets-Sheet 6 Filed May 17, 1961 ML TER flew/En; Sr-EPHEN BAR/(s2, ,psecwaz. MH INMIAI-EE;

INVENTOR S Dec. 29, 1964 w. BENNETT ETAL 3,163,306

MULTIPLE UNIT TRAILERS AND CONTAINERS Filed May 17, 1961 14 Sheets-Sheet '7 Dec. 29, 1964 w. BENNETT ETAL MULTIPLE UNIT TRAILERS AND CONTAINERS 14 Sheets-Sheet 8 Filed May 17, 1961 M1. TEE Hem/Eff STEPHEN 342x52,

.pEQC/VAL A1. HEwM/LLEQ,

1 N VEN TOR5 ffi MW Dec. 29, 1964 W. BENNETT ETAL MULTIPLE UNIT TRAILERS AND CONTAINERS Filed May 17. 1961 14 Sheets-Sheet 9' Dec. '29, 1964 w. BENNETT ETAL 3,163,306

MULTIPLE UNIT TRAILERS AND CONTAINERS Filed May 17'. 1961 .14 Sheets-Sheet 10 INVENTORs,

Dec. 29, 1964 w. BENNETT ETAL MULTIPLE UNIT TRAILERS AND CONTAINERS 14 Sheets$he,et 11 Filed May 17, 1961 W33 rEQ ,Rsmvsn; "Snap/45w BARKEAZ, ,pERC/VAA, M- H/NM/ALE/g INVENTORS imafi MM! Dec. 29, 1964 w. BENNETT ETAL 3,163,305

MULTIPLE UNIT TRAILERS AND CONTAINERS Filed May 17. 1961 14 Sheets-Sheet .12

1&9 M2223. J69 646 73a.

I I WAArE/Q BENA/Efl; i I

SfE-PHEA/ ,BAEKE'E} Pena/v.41. M. .Hwmueg INVENTORS Dec. 29, 1964 w. BENNETT ETAL 3,153,306

MULTIPLE UNIT TRAILERS AND CONTAINERS Filed May 17, 1961 14' Sheets-Sheet l3 ,fi/na: 24.

,JG/Ili" 25.

INVENTORS. A TWLTEQ Rem/Err;

STEPHEN .BAm EQ, .RsRc/mz. Al. JYE/MMIME Dec. 29, 1964 w. BENNETT ETAL 3,163,306

MULTIPLE UNIT TRAILERS AND CONTAINERS Filed May 17. 1961 14 Sheets-Sheet l4 64., INVENTORS. TVZLTER BEAM/E77;

STEPHEN BAQ (fiQ, fiERc/wz. M HEwM/MER,

United States Patent Thepresent invention relates generally to what may be termed composite trailers and/ or containers; and is characterized generally by multiple semi-trailer units that may he used either separately or coupled together to form either a single composite semi-trailer or a series of semitrailers; and registered containers which are moved into coupling registration when semi-trailer units are coupled toform a composite semi-trailer. It is one of the features of the invention that the semi-trailer units are framed independently of the containers, the container framing forming no necessary part of the trailer framing. The trailer or trailer-frame units may thus be used either independently of the containers, or co-operativeiy with containers registered on them for coupling registration. And

it is also a characteristic of the invention that the containers, singly or doubled, may be used and handled independently of the trailer units; the invention also including a container coupling system that may be used independently of the trailer units for coupling containers together to be handled as a single unit.

Although the invention, as will become apparent, may involve more than two coupleable trailer or trailer-frame units, and containers, it will here be described in typical and illustrative form involving two units, but without limitation thereto. For descriptive purposes those two units will be referred to as forward and rear units.

In typical and preferred form, each trailer unit, adequately framed, has a rear running gear, a forward fifth wheel member including a king-pin, and a forward support, so that each may be used separately behind a tractor truck. The several units have engaging formations which, upon coupling, form the several units into a single composite trailer with a rigid composite frame. The rear running gear of the forward unit is then moved out of contact with the roadway under that unit. In one form to be described that movement of that running gear is effected by raising the forward end of the front unit on the tractor; in another form, by'shifting that running gear rearwardly to a position under the unit that is to the rear.

In typical and preferred form the forward unit also carries at its rear end a fifth wheel member similar to that on the tractor. The forward fifth wheel member on the rearward unit may be towed behind the forward unit. And when the two units are rigidly coupled by inter-engagement of longitudinally over-lapping parts, locking of the rear unit king-pin in that rear fifth wheel member locks the two units together longitudinally.

The inter-locked composite trailer may be used for carrying any desired load; but an additional feature of the invention involves containers so registered on the several trailer or trailer-frame units that when the units are rigidly coupled, the several containers are moved into end-to-end coupling registration. .Two or more such coupled containers may then be transferred from one carrier to another as a single unit. That, for instance, may be done by lifting tackle; or, as described below, by running the composite trailer frame out from under the then independently supported composite container unit and running another carrier under the container units.

Various other preferred features of the invention will be best understood from the following descriptions of the typical and illustrative forms shown in the accompanying drawings in'which:

FIG. 1 is a side elevation of a tractor towing forward and rear semi-trailer units connected in series without their frames being interlocked.

FIG. 2 is a side elevation similar to FIG. 1 showing the frames, and the containers thereon, of the two semitrailer units interlocked to form a single composite semitrailer and composite container towed by the tractor.

FIGS. 3, '4 and 4a are schematic side elevations illustrating respectively a rear semi-trailer unit and a forward semi-trailer unit connected to the tractor for towing.

FIG. 5 is a perspective viewed from the rear of the forward semi-trailer unit detached from the tractor, the

forward support legs being lowered into supporting posiof the forward semi-trailer unit taken on line 9-9 of FIG. 1.

FIG. 10 is a side elevation of the frame of the forward semi-trailer illustrated in FIG. '9.

FIG. 11 is a rear elevation of the frame of the forward semi-trailer unit taken on line 11-11 of FIG. 10.

FIG. 12 is anenlarged plan on a scale somewhat smaller than that of FIG. 9, of the frame'of the rear'semi-trailer unit taken on line '12-12 of FIG. 1. FIGS. 16'and 16:; show parts of the two frames at the same scale.

FIG. 13 is a side elevation of the rear semi-trailer unit.

illustrated in FIG. 12.

FIG. 14 is a combined fragmentary elevation and vertical section taken on line 14-14 of-FIG. 13, showing the interlocking elements on the rear semi-trailer.

FIG. 15 is a fragmentary vertical section on-line 15-15 of FIG. 13.

FIG. 16 is an enlarged combined elevation and fragmentary vertical section. through overlapping portions of the frame of the two semi-trailer units when interlocked as in FIG. 2 to form a single composite semi-trailer.

FIG. 16a is a plan of the overlapping parts shown in FIG. 16.

FIG. 17 is a fragmentary perspective of overlapping portions of the two trailer frames illustrating wedge means for securing a tight fit in registration.

FIG. 18 is a side elevation of a second form of the invention, withtwo semi-trailer units interlocked to form a single composite semi-trailer.

FIG. 19 is a fragmentary'plan view on line 1-19 of FIG. 18 of the two interlocked semi-trailer frames.

FIG. 20 is a fragmentary vertical section on line 20-20 of FIG. 19 through the overlapping portions of the two semi-trailer frames illustrating the manner of interlocking the two frames. 7

FIG. 20a is a fragmentary perspective of the overlapping portions of the two trailer frames in position to be engaged by relative longitudinal movement. 1

FIG. 21 is a bottom plan view on line 21-21 of FIG. 18 of the overlapping portions of the two trailer frames slightly separated.

FIG. 22 is an enlarged vertical transverse section on line 22-22 of FIG. 18.

FIG. 23 is a schematic perspective illustrating the a 3,1533% Ice rateateahee. 2a, 1964 I mechanism for raising and lowering supporting legs on the semi-trailer frames.

FIG. 24 is a further enlarged fragmentary vertical section in the plane of FIG. 22 illustrating the manner of 2 locking the cargo container to the semi-trailerframe.

trailer frames interlocked to form a composite semitrailer showing the displacement of the running gear from under the forward frame to a position under the rear frame. 7 1

FIG. 29 is a' schematic elevation illustrating the manner of elevating the cargo containers to permit withdrawing the composite semi-trailer frame from them.

FIG. 30 is a schematic perspective view illustrating the construction and movement of supporting legs on the cargo containers.

Referring now to .the drawing, and particularly to FIGS. 1 and 2 wherein there is shown in side elevation a presently preferred embodiment of the present invention, it will be seen that the semi-trailer units are connected to a prime mover indicated generally at it). This prime mover is a truck-tractor, more simply referred to hereinafter as a tractor, to which the semi-trailer units are connected to be towed. The tractor may be of any suitable.

design and construction and includes a fifth wheel element 12 mounted on therear portion of the tractor chassis where it isIaccessible for connection to the' forward fifth wheel element on a semi-trailer unit. Element 12 is a V plate-like member mounted to tilt about a transverse horizontal axis by pivot 13. Except as laterv described, the

to receive apin element .on the trailer being towed; This particular conventional construction is the same asis disclosed in connection with the'semi-trailer units.

Connected to the fifth wheel 12 on the tractor is semi-' trailer, or trailer-frame, 14/ referred to herein as the forward semi-trailer unit. Behind semi-trailer 14 and connected to it, as will be described later in detail, is a second semi-trailer, or trailer-frame, 16,.referred to as the rear semi-trailer unit. The semi-trailer units are different in construction as willbecome apparent, and the forward unit is more versatile in its uses. Both of the semi-trailers are alike in that each has a frame which is supported upon suitable running gear located at the rear portion :of the frame, and, for certain connective assemblies, a slidably mounted fifth wheel element located on the forward portion of the frame which supports the trailer on a-'tr actor or another trailer. Mounted on each of the two semitrailers, or semi-trailer frames, isa cargo container 17 and 18 respectively. 7

in their preferred form, these cargo containers have features which will be described in detail later; but in the broad aspect'of the'present invention, these containers may be of any size, shape or construction carried upon the two semi-trailers. V

The construction of the frame of the forward trailer unit 14 will be apparent from FIGS. 9 and 10. The frame adapted to be underneath.

fifth wheel unit 12 is of well known'design and comprises i essentially a plate with'a rearwardly facing slot adapted comprises a pair of spaced, parallel, longitudinally extending beams 2tiof which but one is shown in each of FIGS. 9 and 10, the trailer being symmetrical about a longitudinal center line 23. These longitudinal members I are connected together by suitable cross members 21 at intervals along the frame and also support a pair of transversely extending bolsters 22 upon which cargo container 17 is mounted. Toward the rear end of the trailer, longitudinal frame members 2% are offset downwardly as shown in FIG. in order to support on the lower rear portion of the frame a rear fifth wheel element 24 at the standard distance above the ground surface. This fifth wheel element 24, like the corresponding forward element 12 on the tractor is a plate, mounted at 24a on the trailer to rock about a transverse horizontal axis, and having a rearwardly facing slot 24b adapted to receive the conventional king-pin of the cooperating fifth wheel element attached to the. rear'trailer being towed from the front trailer. At its rear end, the frame of trailer unit 14 is supported on a wheel and axle assembly indicated generally at 25 which may be of any suitable construction and supports the trailer on the ground.

At its forward end, the semi-trailer unit 14 is provided with a forward fifth wheel element, including king-pin as. Pin 26 projects downwardly below the trailer frame from a fifth wheel plate and is adapted to be received in the rearwardly facing slot in fifth wheel element 12 mounted on the tractor, thus allowing the trailer to swing horizontally about a vertical axis established by the pin 26, relative to the tractor. A suitable latch mechanism in fifth wheel element 12. holds the pin 26 seated at the forward end of the slot in the plate 12. This latch shown schematically at 27 in FIG. 10 may be the same as the latch 28 associated with fifthiwheel plate 24 at, the rear of the trailer, the latch being urged forward into the locking position shown in FIG. 9 by spring 29 and retractable to permit disengagement of the pin from the slot by manual manipulation of handle 30 which projects laterally from beneath the plate 24.

The forward fifth wheel element 26 is slidably mounted upon the trailer frame for movement between the rear position shown in solid lines in FIG. '10 and the forward position 26a shown in broken lines. This is accomplished by mounting king-pin 26 in block 32 which is slidably mounted between a pair of guides 33 for movement longitudinally of th'etrailer frame. 7

Mounting block 32 islocked in therearward position 7 position shown in broken lines in FIG. 9. The two latches '34 and 36 are simultaneously retracted, to allow block 32 free movement between guides'33, by means of handle 38 when pulled downwardly in the figure. Handle 38 is pin connected at 39 to one arm of bell crank 40 which turns about fixed pivot 41, the other arm of the crank being connected to locking bolt 36.

In a similarmanner handle 38 is pin connected at 39 to link 32 which in turn is connected to one arm of bell crank 43 which swings aboht fixed pivot 4-4 and is connected to the first latch bolt 34.

The reasons for shifting king-pin 26 longit'udinally of the trailer unit will be more fully understood from further description.

At each side of the trailer frame is a vertical guide 37 depending from a side beam 2%. These two guides 37 are so disposed with respect to the end of the frame of tractor 10 that the tractor frame fits between and engages the two guides, with normal working clearance, when king-pin 26 is in the rearward position, as shown in FIG. 1, butdisengages the guides when the king-pin is in the forward position 25a.

Each of the two semi-trailers is provided with interfitting means engageable by relative longitudinal moveme'ntof the trailers to join the frames of thetwo trailer uints together to form a single effective rigid frame. On the forward trailer unit the interfitting means consists of a variety of sockets. One of these sockets is a tapered socket formation formed between longitudinal members 20 by a pair of wedges :5, of which only one is shown in FIG. 9, the other being symmetrically located with respect to the longitudinal center line 23 of the trailer as may be seen in FIG. ll. These wedges 45 are each mounted on one of the longitudinal frame members 20 rearwardly of a transverse member 21 and provide a pair of forwardly converging faces 46. The forward portion of the frame of the rear trailer 16 is slidably received between the opposing faces 46, as will be later described.

The two wedges 45 are tapered both vertically and horizontally at their rear ends as seen in FIGS. 9 and it in order to guide the channel of the rear trailer unit more easily into the tapered socket formation on the front trailer. In order to take up any inaccuracies in manufacture and to provide a snug fit between the frames of the twotrailers there may be provided a plurality of tapered shims48 on one or more of the top, bottom and side faces of the wedge members 45, as may be seen in FIGS. 9 and 17. The rear socket means on the forward trailer are two in number and are indicated at 50. These sockets 5d are rectangular sleeves with rearwardly flared openings mounted on the rear cross member 21, as shown particularly in-FIGS. 9, 10 and 11. The two sockets 59 are spaced apart laterally of the trailer and are located rearwardlyfrom the tapered socket formation previously de scribed to give the desired overlap for rigidity to the composite trailer formed by the two trailer 'units when joined.

In order to support the front end of trailer 1 when the trailer unit is not connected to and supported by the tractor, the trailer is provided at its forward end with a pair of out-rigger-type legs 52, one on each side of the frame. Each leg is an angular member, having a horizontally extending portion rotatively and slidably mounted in a sleeve 53 attached to the forward transverse leg is swung downwardly into contact with the ground as shown in FIG. 5. When the trailer is being towed, the leg is swung upwardly through an arc of 9 to the carrying position shown in FIG. 1. It is secured in thi carrying position by passing it between the bifurcated end of bracket 54 (see FIG. 10) which projects outwardly from the side of the-trailer frame, a locking'pin 55 being slidable in the spaced end portions of the holding bracket to hold the leg in position. The leg slides'in its associated sleeve in order that it may move horizontally into carrying positon between the. ends of bracket 54. A second locking pin 56 (FIG. 9) is passed through registering holes in leg 52 and sleeve 53 in order to lock the leg in the down or load supporting position.

The frame of the rear semi-trailer unit is shown pmticularly in FIGS. 12 and 13. It comprises a pair of longitudinally extending frame members (all which throughout much of their length are parallel to each other. The forward portions 6th: of these longitudinal members converge forwardly at tla to provide a tapered formation interengageable with the tapered socket formation on the front trailer. The taper of the members 69a conforms to the taper of wedge faces 46 of the wedges 45, as these portions of the two longitudinal members on the rear trailer are members on that unit which interfit with wedges 45 on the front trailer to join the two trailer units together. The trailer frame also includes a plurality of cross members 61 at intervals along the length of the trailer, together with suitable braces to give strength and rigidity to the trailer structure. The forward cross mem her 610 is in effect a part of the means interfitting with the members on the front trailer. On top of the longitudinal frame member 6% are two transversely extending bolsters 62 on which the container 18 is supported.

At the rear end, the trailer 16 is supported on a wheel and aide assembly 63, which may be of any suitable de sign and attached to the trailer frame in any suitable manner. For supprt at the forward end when not connected to a tractor or a forward trailer unit, the trailer is provided with a conventional pair of retractable and extensible legs 64 mounted one on each bracket 65. When lowered, the two legs 64 appear as in FIG. 13. In this position wheels 66 on legs 64 engage the ground to support the trailer and the load thereon.

Extension and retraction of the legs may be accomplished by any suitable construction, various arrangements being well known in the art. As illustrative of such means, each leg is made in two telescoping sections,th'e upper one of which may beprovided with a fixed .nut 7d and the other a screw 71 as indicated in phantom lines in FIG. 23. When the screw 71 is rotated by means of a pair of bevel gears 72 through the agency of crank 73, the lower leg section 64b is extended from or retracted into the upper leg section. .Changing'the'length-o'f legs 64 is advantageous for various purposes, including locating the forward fifth wheel element on the rear trailer'uriit at the proper height above theground to'be received by the rear fifth wheel element on the front trailer unit.

Disposed rearwardly of the frame members 60a are two tapered plugs 75, located one at each side of the frame on a bracket '65. These two plugs are'the rear interfitting elements carried by the rear trailer to engage complementary elements 5%) on the forward trailer. They are rectangular in cross section and of a sizeto fit snugly within the tapered sockets St? on the'forward trailer unit. For this reason thetwo plugs 75 are located below the frame members till of the rear trailer and at such a height a above the ground that the plugs can be inserted in sockets Si} by relative longitudinal movement of the twotrailer units when they are coupled together.

The forward end of the rear semi-trailer unit 16 is pro vided with a forward'fifth wheel element in the form of king-pin 76 which is designed to be receivable within the lished by the king-pin, provided that such movement of the rear trailer is not otherwise restrained or prevented. The forward fifth wheel element 76 is mounted upon the frame of trailer 16 for longitudinal movement relative to the trailer between the forward position, shown in FIGS. 12 and 13 in solid lines, and the rearward position, shown in broken lines. This longitudinal movement is made possible by mounting king-pin 76 on block'77 which .is slidably mounted between guides '79 for movement longitudinally of the trailer frame. Block 77 is locked in the forward position of FIG. 12 by a latch fiil'which is normally urged intofthe locking position by a spring (not shown). Vfhen moved rearwardly on the trailer frame to the rear position, block 77 is locked in the rear position by a second latch pin $2. The twolatches 89 and 82 may be simultaneously retracted, in order to allow block 77 free movement parallel to guides 79 by means of a linkage connected to both of the latch pins. Such linkage includes an operating handle 84 connected to one arm of bell crank 85 which rocks about fixed pivot 86, the other arm of the bell crank being attached to the outer .end of latch 3%. Handle 34 is connected also by link 87 .to a

second bell crank 88 which rocks about a fixed pivot 89,

the other arm of the bell crank being attached to they rearward latch 82. It will be seen that as handle 84 is manipulated manually by pulling it in the direction of the arrow in FIG. 12, that the linkage just describedoperates to retract both of the latch pins in opposition to springs With this arrangement, king-pin 26 normally is in the rearward position which moves the semi-trailer unit up to the close coupled position. This close coupled position is occupied by forward trailer unit 14 in FIG. 1 in zontal and vertical movements of a semi-trailer. combination the rear trailer, is being towed by the forward trailer; and the two trailer units are operating independthe ground surface.

which the guides 37 engage the tractor body to prevent the trailer from swinging horizontally relative to the tractor. The effect is that of a single vehicle with a tandem axle assembly composed of the rear afle ofthe tractor and the running gear 25 of the trailer unit. Of course' the two vehicles have an articulated connection at the fifth wheel which permits limited vertical movement of the trailer relative to the tractor about pivot 13.

Under some conditions greater maneuverability may be desired and this can be achieved by towing the front trailer unit as a semi-trailer free to swing horizontally about king-pin 26. This is'accomplished by moving the king-pin forward to 26a, which shifts the trailer rearwardly relative to the tractor. This position of the trailer unit is shown in FIGS. 2 and 4 wherein the tractor frame no longer engages vertical guides 37'. I

It is also possible to towthe rear semi-trailer unit 16 alone, as shown in FIG. 3. This is done by coupling the rear trailer to the tractor by inserting king pin 76 in the slot 24b of the fifth wheel element 12 on the tractor.

Normally the king-pin occuplies the forward position shown in FIG. 12 when coupled directly to the tractor; butthe king-pin may be moved to the rearward position 76a if space considerations permit. Whenever the rear trailer unit 16 is being towed, the wheels on extensible legs 64 are raised out of ground engagement by turning handle 73, as previously described. This enables the full weight of the trailer and its load to be carried upon the running gear 63 and the tractor 10. V

A fourth arrangement is one including both trailers as shown in FIG. 1. In this combination of units, the forward trailer is connected directly to the tractor, as in FIG. 4, and the rear trailer unit 16 is then coupled to the forward trailer by connecting theiifth wheel elements on the two trailer units. In this combination, king-pin 76 is in the forward position shown in full lines in FIG. 13 allow ing the rear semi-trailerunit the normal range of hori- In this ently and each has its own running gear in Contact with A fifth combination of units is that shown in PEG. 2. This combination is derived from the combination of units illustrated in FIG. 1 by moving the forward trailer unit longitudinally back with respect to the front trailer unit to close the gap between them. ltis most practical to block the rear trailer wheels and move the front trailer with the tractor. This longitudinal movementlismade possible by the range of movement to which king-pin 76 is adapted, the king-pin being moved to the rearward position 76a to accomplish this combination of the elements. As the rear semi-trailer unit is moved forwardly, the inter engaging formations on the two units are brought into .on the forward trailer to overlap these wedge sections.

The forward section 66a of the rear trailer beam is preferably in the shape of an I-beam or a channel having flanges which engage both the upper and the lower surface of each of the wedges 46. See FIG. 11. Inequalities in manufacture can be compensated for by one or more shims 48 which assure a snug interfitting between the ele- V ments of the two trailer units.

The same relative longitudinal movement of the two trailer units causes plugs 75 to enter and engage the walls 7 the sockets 50 at the rear of the forwardtrailer unit. I

The engagement of these units is shown in detail in FIGS. 16 and 16a. The plugs 75 are a sizeand shape that fits snugly within the sockets and have their forward ends tapered as illustrated to facilitate entry into the sockets.

Plugs 75 and sockets 54 include both vertical and hori-.

' trailers overlap as illustrated in FIGS. 16 and 16a.

zontal tapers to'bring the two frames into proper fit in spite of any initial misalignment of the parts.

It will thus be apparent that on the two trailers there are two sets of complementary, mutually engaging elements which interfit both laterally and vertically at longitudinally spaced positions of the two trailer units. The forward set of inter-engaging elements includes the members 66a and the wedges 46 on the rear and front trailers respectively. The rearward set of inter-engaging elements includes plugs 75 and sockets 5t moved into this interengaging position portions of the Relative movement of the two trailers is prevented by locking the king-pin on the rear trailer in the rear position and locking it in the fifth wheel 24 of the forward unit. Be: cause of the interfitting of elements on the two trailers, their interengaging fifth wheel elements no longer perform all the functions of the usual fifth wheel arrange ment but they do serve to lock the two trailers in position with respect to each other to form a single rigid composite trailer and to transmit the tractive force from the. forward portion of this rigid trailer to the rearward portion.

When the two trailer units are a single composite trailer, it may be desired in special situations that the running gear of the forward trailer unit be moved out of contact with the ground surface in order to gain greater maneuverability of long trailer; This is gained by having only one pair of wheels downon the road While various other arrangements are possible for this purpose, in the form of the invention illustrated in FIG. 2, the front end the rear trailer. bolsters are of the same size and shape on both trailers of the composite trailer is elevated sufiiciently to lift the wheels of the forward running gear 25 out of contact with the road surface as shown in FIG. 2. This is accomplished by mounting the tractor fifth wheel element 12 on base plate 9t), the base plate being attached to the chassis of the tractor by two pairs of parallel links 91 which permit the base plate to be raised and lowered relative to the tractor chassis while still maintaining the base plate in a horizontal position. Thebase plate is raised and lowered by piston and hydraulic cylinder 93, the end of the piston rod being attached to the under side of base plate 99. By fillingQthe cylinder with hydraulic fluid under pressure, from some suitable source not illustrated, the piston is urged to the end of the cylinder, forcing base plate 99 upwardly and raising the forward end of the composite trailer. This in turn lifts wheels 25 off the ground, as shown in FIG. 2 and only the running gear on the rear trailer is in engagement with the ground and supporting the trailer.

For ordinary over-the-road use, the composite trailer is operated with the wheels of both axles on the ground to carry the load. A fifth wheel plateof usual design may be used in the tractor, such a wheel having the pivot 13 mounted onthe chassis of the tractor. This usual design is non-elevating and is shown in the schematic FIGS. 3 and 4. The elevating type of fifth wheel just described is intended to meet special stiuations and is not necessarily limitative upon the invention.

The trailer units so far described may carry any kind of cargo or cargo containers. 'For example they may be supplied with fixed bodies. However, in the preferred embodiment the present invention contemplates removable containers having certain structural features as will now be described in order to obtain further advantages of the invention.

Each of the two trailer units 14 and 16 carries a cargo container 17 and lsrespectively. Each container is supported upon the trailer by two transversely extending bolsters, indicated at 22 on the forward trailer and 62 on For purposes of interchangeability, the

and are spaced apart longitudinally of the trailer the same distance. Likewise, the cargo containers 17 and 18 are When once the vertical face of end wall 17a of the container.

planar with the side wall 17b of the container.

duplicates of each other so that the description of the container on the forward trailer unit will suifice for both. Referring to FIGS. 1 and especially, it will be seen that the bottom of the container 17 is provided with inverted transverse channels 94 at two spaced positions beneath the floor of the container in order to receive the bolsters 22. As shown in FIG. 15, each channel 94 is closed at the lateral ends by a longitudinal beam member 95 which engages the ends of the bolsters. Container 18 has similar closed-ended channels, indicated at 94, engaging over the bolsters 52 of the rear unit. Thus the closed-ended channels at the bottom of the containers hold the containers against shifting either longitudinally or laterally on the trailers. In addition, it is desirable to provide some type of tie-down means. While such means are well known in the art and any suitable type may be employed, as typical of suchmeans there is here shown a cable 96 having a hook 97 on the free end which is engageable with an opening 97a in the container, as shown particularly in FIG. 15. The cable is wrapped around a drum 98 by means of which the cable may be tightened. A holding pawl engaging a ratchet wheel 99 on the drum prevents reverse rotation of the drum after the cable hasbeen tightened.

The bolsters 22 and 62 are located at predetermined positions on the trailer frames and thereby each container.

is located at a predetermined position upon the respective trailer and with respect to the elements of the trailer. Advantage may be taken of this feature to efiect an interfitting engagement of the containers on the two trailer units by moving the trailer units into position with their frames interfitting as in FIG. 2.

Each of the containers is rectangular in plan and is provided at each of the four corners with a vertical columnar formation by which such engagement of the containers is effected. Referring now particularly to FIGS. 7, 8 and8a, it will be seen thatthe container 17 has at one corner a vertically extending column formation indicated at ltlfi which projects outwardly beyond The column formation 1% is so located with respect to the corner that one face of the column is substantially co- As indicated schematically in FIG. 8a, the same columnar formation is provided at the diagonally opposite corner of the container where the column projects endwise beyond the other end wall 170. Y Y

At the two remaining corners of the container, which are diagonally opposite each other, the container is provided with a vertical columnar formation of the type indicated at 162. It will be noted that this formation is removed inwardly from the side face 17 b of the container projects beyond end wall 17a.

At the ends of the container and spaced from but parallel to column formations Hi2 there is located near the top corner of the container plate 163 and near the bottom corner of the container plate 164. Each of the plates 103 and itl is provided with a hole aligned with a similar hole in the column 1&2, so that a pin 1'95 can pass through the openings in both plate H93 and the column formation and a similar pin 1&6 can pass through aligned openings in plate 104- and column 162. From FIG. 8 it will be noticed that each column formation 10,0 isprovided with upperand lower openings 197 which are at the same distance above the bottom of the container as the pin-receiving openings in column H32 and therefore can be movedint-o registration with the openings in columns 102 and plates M3 or 1% in an adjoining container to receive pins 1% or 166 as shown in FIG. 6.

Each pin 1% and 1% is provided with ahandle 1th; to assist in inserting and removing the pin and which is 7 id received behind keeper plate res to hold the pin against accidental displacement.

The registered positions of the two containers l7 and 18 on the two trailer units are such that when the trailer units are brought into the rigid interfitting position of PEG. 2, the interfitting corner column elements on the two containers are brought into registration to interfit with each other as in FlG. 8a. As shown particularly in FIG. 6, the projecting column 1% of container 18 is now in position adjacent column 162 of container'17 and between the column and the plates 1% and 1%. Likewise, as indicated in FlG. 8a, column tee of container 17 is in the same interiitting relation to column 192 as container 18. The lower pin receiving holes in these pairs of three members are in horizontal registration so that pin 1% may pass through all of the lower holes to lockthe two containers securely together. The same is true of the upper sets of holes receiving pin 165. The containers are thus locked together in end-to-end relation by four pins, two

pins The at the upper corners and two pins 1% at the lower corners. The coupled containers may now be handled as a single unit when they are removed from the trailer.

Each column formation 1% and 102 is provided near the top with an opening 111 of a size to receive thehool: or projectible bolt of a hoisting bridle. The containers can be handled individually if desired, or in coupled pairs by inserting the hooks (not shown) in the openings 11 1 at the four corners of a single container or a coupled pair as the case may be. In the latter case, thectwo lower pins 1% are especially relied on to hold the containers against relative displacement in any direction. Similar openings 111 are provided near their bottoms throughthe columns, to receive hold-down members. The general relations of the columns and their openings to their respective container bodies is a subject matter'of application Serial No. 840,606, filed September 17, 1959, by Percival M. Heinmiller and Stephen Barker.

There is shown in FIGS. 18 through 36 a variational form of our invention in which certainof the parts are different in form or construction but still similar in func tion to the embodiment of the invention just described. The alternative embodiment will now be disclosed briefly with special reference being made to the diiferences in construction and operation between the two embodiments.

This second embodiment of the invention comprises a forward semi-trailer unit 114 which can be connected to the fifth wheel 12 of the tractor 10 for towing thereby.

Behind semi-trailer unit lie and connected. to it in .a

manner which will be described, is a second semi-trailer unit are which is the rear semi-trailer unit of the pair. These two trailer units are each longer than in the embodiment previously described so that each trailer unit is capable of carrying two of the same sized cargo containers.

Thus in FIGS. 2628 it will be seen that two cargo containers ii? and 11% are loaded on the forward trailer unit while two cargo containers 11S and 113a are loaded onto the rear trailer unit. It will be understood that ths arrangement is a matter of relativesizes and is not limitative upon the invention since each trailer unit may be designed to carry one or more cargo containers. Each of the cargo containers is constructed as previously described and the two carried on a single semi-trailer unit, as 117 and 11%, are preferably inter-locked end-to-end in the manner already disclosed.

The construction of the frame of the forward trailer 114 l near its front end with a fixed forward fifth wheelelement, king-pin 12d beneath plate 123, which is adapted wheel element is adapted to receive the cooperating forward fifth wheel element-a kingpin-on the rear trailer unit. The fifth wheel plate126 is provided with latch Toward its rear end, the same semi-trailer unit mechanism 127 of the type already described which locks in place the cooperating element of the rear trailer and thereby locks the two trailers together when they are in position to form a single rigid trailer frame.

When the forward trailer 114 is operating alone it is supported at the rear end by a wheel and axle assembly 128 of any suitable design which provides running gear for the trailer at the rear end. One of the features 'of the present invention is that this running gear is shiftable with respect to the trailer; but the means by which this shifting is accomplished will be more easily understood after the description has progressed further. 7

In order tosupport the forward end of trailer 114 on the ground when uncoupled from the tractor, or to'support the trailer and load independently of the running gear 128, the trailer is provided with at least one pair and entire trailer may be supported in a stableposition upon the four legs 64.

As in the first embodiment described, so in the second embodin ent each of the two semi-trailers is provided with interfitting means engageable by relative longitudinal "movement of the two trailers to join the frames of the two trailer units together to form a single effective rigid frame.

On the forward trailer unit this means includes as the forward element a pair of laterally spaced sockets 122:: on the transverse beam 122, as shown particularly in FIGS. and 20a. The rearward interengaging elements on the forward trailer frame are the two tapered extensions 130 located one at the rear end of each longitudinal side beam 129. These extensions 134) are tapered both horizontally and vertically as may be seen particularly by reference to FIGS. 21 and 26.

The frame of the rear semi-trailer unit 116 is shown in FIGS. 18, 19 and 20a; and comprises a pair of spaced, longitudinally extending side beams 135 which are interconnected by a plurality of transversely extending cross members 136 at intervals throughout the length of the trailer frame. Disposed just inside of and projecting beyond the ends of side beams 135 is a pair of forwardly extending members 137 which are adapted to be received in and to interfit with the sockets 122a in the cross beam 122 of the forward trailer unit. The tips of these. extensions 137 are preferably tapered both horizontally and vertically as may be seen particularly in FIGS. 19 and 20 in order that they may be more. easily guided into sockets 122a and correct any initial misalignment of the two trailers. Rearwardly of the forward end of the rear trailer unit and spaced longitudinally from the members 137, the rear trailer 116 is provided with a pair of tapered sockets 133 just inside of the side frame members 135, each of which sockets is adapted to receive the. end of one of the tapered extensions 13%) which projects beyond the side beams of the forward trailer.

When portions of the trailer frames are overlapped to bring these interfitting elements into engagement as shown in FIGS. 19 and 20, the two trailer units 114 and 116 be-.

' side beams 135 of'the rear trailer.

come a single rigid trailer frame which is inherently adapt: ed to support upon itself any suitable load. FIG. 20a shows in perspective the overlapping portions of the two trailer unit frames ready to interengage as a result of 1on gitudinal movement. The paths of the interfitting elements on the two frames are indicated by broken lines with arrows. Moved into engagement, the frames appear 'as in FIGS. 18 and 19.

At its forward end, the rear trailer unit 116 is provided with fixed king-pin 140 carried beneath plate 146 which is cngageable with the fifth wheel plate 126 of the forward trailer unit or with the plate 12 of the tractor, depending upon whether the rear trailer unit is operating in conjunction with the forward unit or operating'separately, as in FIG. 27 which shows the rear trailer'alone being towed by the tractor. Inter-engagement of these fifth wheel elements locks the two trailer units together. Rear trailer unit 116 is likewise provided with two pairs of extensible legs 64. One pair is located forwardly on the trailer frameand' the other pair rearwardly on the trailer frame, as seen particularly in FIGS. 18 and 27. One departure from the leg structure already described is that the forward pair of legs'64 is not fixed .but is swingingly mounted outside of or laterally beyond the This location of the legs is advantageous since the legs may be rotated through an arc of approximately between an upright posi tion in which they support the load and a horizontally extending position, as shown particularly inFIG. 28, in which the entire leg structure is raised above the lower flange of the side beams in order to permit shifting of the movable running gear 128, as will be described.

This movement of the legs is accomplished by the structure shown schematically in FIG. 23 in which the 7 may be rotated by meansofyattached'crank 143. By

winding the cables on the drum, the legs are lifted to the horizontal position and held in that position by engaging pawl 144 with ratchet 145 which is rigidly connected to drum 142. When the pawl is disengaged from the ratchet the weightof the legs is sufficient that they drop by gravity to the load supporting position. In order to permit this swinging movement of the leg 64, the knee braces 147 are either provided with detachable fastenings at V the upper ends so that they may be disconnected from the frame of the traileror else are made in two pivotally interconnected sections, as is well known in the trailer art.

At the rear end, the trailer unit 116 is provided with the usual running gear in the form of a wheel andaxle.

assembly 148 which may be .of any suitable design. This running gear may be attached to the trailer frame at a fixed location, as is usual.

2 However, it is one of the features of the present invention that the running gear 128 may be shifted between the position of FIG. 26 in which it is under the forward trailer 114 to the position of FIG. 28 in which the running gear 128 is under the rear end of the rear trailer unit. In order to accomplish this longitudinal shifting movement of the running gear 128, the axle is attached to a frame 15f shown particularly in FIG. 22 which slidably and supportingly engages. the undersurfaces of side rails on the two trailer units.

Each of the side beams and of the two trailer units has the shape and cross section of an I-bearn, as may be seen by reference to FIGS. 20a and 22 wherein ,V the longitudinal beams 135 of the rear unit are shown. The bottom flanges of the side beams rest upon the top of the wheel frame 150. The wheel frame 1511 is also 

1. THE COMBINATION OF A PLURALITY OF LONGITUDINALLY JUXTAPOSED SEMI-TRAILER UNITS, EACH UNIT HAVING A FORWARD FIFTH WHEEL ELEMENT ADAPTED TO COOPERATE FOR TOWING WITH A FIFTH WHEEL ELEMENT OF A TOWING VEHICLE, AND EACH UNIT HAVING A PERMANENT REAR RUNNING GEAR, THE REAR PART OF A FORWARD ONE OF SAID UNITS AND THE FORWARD PART OF A REARWARD ONE OF SAID UNITS HAVING INTEGRATED RIGID PORTIONS FORMED FOR LONGITUDINAL OVERLAPPING INTER-FITTING BY RELATIVE LONGITUDINAL MOVEMENT, TO RIGIDLY JOIN THE TWO UNITS TO FORM AN EFFECTIVE SINGLE UNIT RIGID IN BOTH VERTICAL AND HORIZONTAL PLANES, AND THE REAR PART OF THE FORWARD ONE OF SAID UNITS CARRYING A FIFTH WHEEL ELEMENT WITH WHICH THE FIFTH WHEEL ELEMENT OF THE REARWARD UNIT IS ADAPTED TO COOPERATE. 